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G. W. KNAPP. Method of Attaching Bottoms to Cylindrical Metal Bodies;No. 232,405.. Patent Fifi 5 l E f 3 i U I l C q 1 If J 22 .4. Fig.5: 6

Witne sses; Inventar:

UNrTED STATES PATENT OFFICE.

GEORGE W. KNAPP, OF BALTIMORE, MARYLAND.

METHOD OF ATTACHING BOTTOMS T0 CYLINDRICAL METAL BODIES.

SPECIFICATION forming part of Letters Patent No. 232,405, datedSeptember 21, 1880.

Application filed August 6,1880. (No model.)

To all whom it may concern Be it known that I, GEORGE W. KNAPP, acitizen of the United States, residing at Baltimore, in the county ofBaltimore and State of Maryland, have invented certain new and use fulImprovements in Attaching Bottoms to Oylindrical Sheet-Metal Bodies; andI do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make -and use the same, reference beingbad to the accompanying drawings, and to letters or figures of referencemarked thereon, which form a part of this specification.

My invention relates to an improvement in the art of attaching bottomsand tops to cylindrical sheet-metal vessels, such as coffeepots,saucepans, fruit-cans, and the like, and will first be described, andthen designated in the claim.

In the accompanying drawings, Figure l is a section of the bottom,showing its form previous to attachment to the body. Fig. 2 is a sectionof a tapering body and bottom placed together preparatory to theirattachment. Fig. 3 shows the manner of attaching the bottom to the body,and illustrates the second stage of the operation. Fig. 4 is a sectionof a straight-sided body and bottom finished. Fig. 5 is a view of astraight-sided cylindrical vessel having both a top and bottom attached.

The letter A designates the cylindrical body of the vessel, which may betaperingor straightsided. The body is seamed at I) in the ordinarymanner, and the lower edge, 0, is left straight, as shown in Fig. 2. Thecircular bottom E is blanked out and pressed in one operation to formaround the edge an inclined part, f, having an outward curved portion,which spreads into a horizontal flange, g.

The bottom may be stiffened, if desired, by slightly convexing it.

The lower edge, 0, of the body of the vessel, which, as seen in Fig.2,is straight, sets around the tapering part f of the bottom, with whichit comes in close contact (see Fig. 2) before it is fully down to thehorizontal flange. In this position the body and the bottom are placedin the chuck of a spinning-lathe, as shown in Fig. 3, and the pressureof the chucks, bearing endwise on the body, brings the edge 0 fully downon the flange of the bottom, so that the operation of locking the bodyin the lathe spreads or flares the edge a of the body, as seen in Fig.3, as it is made to conform to the outward-curved portion of thetapering partf and flange g of the bottom.

Any suitable tool may be used to turn by the spinning process the flangeg of the bottom. This tool consists, preferably, of a grooved roller, i,having the flange on one side of the groove projecting to a greaterextent than the flange on the other side, and suitably mounted. Thisgrooved roller is now brought to bear on the flange g of the bottom,(see Fig. 8,) which is thereby turned over so as to inclose the flarededgeof the body, and is made to bear againstthesurfaeeof the latter.Thereby the flarededge of the bodyis tightly clasped between thetapering part f of the bottom and its turned-over edge, as seen in Fig.4. By this construction a base rim, n, is formed, which supports thevessel, keeping the bottom from contact with any surface on which thevessel may be set, and is for this reason especially. adapted forsaucepans, kettles, and the like.

Both the construction shown and the several described steps whichcomprise the method are applicable to vessels which have two headssecured, such as fruit and oyster cans, as shown in Fig. 5. In such theflange of the two heads, by the use of a twin tool, like roller i, maybe spun or turned up at one and the same time.

I am aware that in attaching bottoms to cylindrical sheetmetal bodiesthe bottom has had an angular flange formed around the rim, the outeredge of which is turned up at an angle to the plane of the bottom, andthat the body has, by a separate operation, had a flange turned outward,which rests upon or against the flange of the bottom, while the edge ofthe body-flange abuts against the outer part of the bottom rim, which isturned up at an angle to the plane of the bottom, and that parts thusformed have both been turned or headed over inward against the body. Ascompared with this my method has the advantage in that 1 save theoperation of forming the outwardtnrned flange on the body, and also savethe metal required for said flange and the opera tion of crimping in theouter edge of the bottom rim, which is turned up at angle to the planeof the bottom. Mine is therefore more expeditious and cheaper.

I am also aware that in other cases the circular bottom has beenprovided with a downwardly-projecting flange which is in contact withthe inner side of the straight end of the cylinder-body, and that theflange of the bottom and edge of the body have been shown as if bothwere turned outward, up, and over inward against the body, forming adouble hollow bead. As compared with this my method has the advantage ofnot injuring the metal of the bottom flange, as is done in the processjust referred to, where the forming of the downwardly-projecting flangecrimps in the edge of the metal, and then the turning of said flangeoutward, up, and over inward first stretches and then crimps it-anoperation of such severity that a low grade of tin will not stand it.Besides, by my method 1 save the metal required in the body to admit ofturning its lower edge; and, further, by my method a bottom can beattached to bodies which are either straight, tapering from bottom totop, or flaring from bottom to top and, furthermore, both a top andbottom can be attached at once.

It will thus be seen that by my process quite an economy is effectedwhere the manufacture is conducted on a large scale.

Having described myinvention, I claim and desire to secure by LettersPatentof the United States- The improvement in the art of attachingbottoms and tops to cylindrical sheet-metal vessels, consistinginstamping or pressing the circular bottom to form around the edge aninclined part having an outward-curved portion, which spreads into aflange, placing the end of the cylinder whose edge is straight or inline with the body around the inclined part of the bottom, with which itcomes in close contact when only part way down, subjecting the parts toa pressure which bears endwise v on the body, thereby flaring its edgeand conforming it to the shape of the bottom, and turn ing the flange ofthe bottom by the spinning process over inward against the body and soas to inclose its flared edge, as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

GEORGE W. KNAPP. Witnesses J NO. '1. MADDOX, (Darts. 13. MANN.

